厦门地铁隧道变形控制指标的确定方法

依托厦门风化花岗岩地层的盾构隧道工程,以土体参数的空间变异性为切入点,针对当前隧道变形控制指标体系存在的针对性不足、科学性不够及适用性不强等问题,结合现场监测数据的统计分析和基于随机场理论的可靠度分析,提出了厦门轨道交通隧道工程变形控制指标的综合确定方法。结果表明:厦门典型风化花岗岩地层中,盾构隧道施工引起最大地表沉降的统计平均值为-13.50 mm,监测数据的95%分位数约为-32.42 mm;根据可靠度分析,最大地表沉降服从标准正态或对数正态分布形式,随机计算所得最大地表沉降的95%分位数为-35.43 mm。从安全角度出发,建议将-35.0 mm作为厦门典型风化花岗岩地层盾构隧道施工地表沉降的控制值。

Determining Deformation Control Index for Xiamen Metro Tunnel

Present control index systems for soil deformation is insufficiently targeted, scientific, and applicable. In view of this, we present a comprehensive method of determining the deformation control index for the tunnel project of Xiamen metro line in weathered granite stratum as an example. The method introduces the spatial variation of soil parameters based on statistical analysis of field monitoring data and stochastic reliability analysis. Results demonstrate that in the typical weathered granite stratum in Xiamen, the statistical mean value of the maximum surface settlement caused by shield tunneling is -13.5 mm, and the 95% quantiles of maximum surface settlement is -32.42 mm. According to the stochastic reliability analysis, the maximum surface settlement is in the form of standard normal or lognormal distribution, and the 95% quantiles of maximum surface settlement obtained by stochastic calculation is - 35.43 mm. From the point of view of safety, we suggest to take -35.0 mm as the control value of surface settlement during the twin shield tunneling in Xiamen typical weathered granite stratum.